The goal is to define molecular events that correspond to estrogen (E) responsive growth and invasiveness in ovarian cancer. While estrogen receptor (ER) is expressed in most ovarian carcinomas, the molecular effects of E and antiestrogens have not been investigated. The proposed studies may facilitate the development of treatment strategies and diagnostic markers. To define the effects of E and antiestrogens, we will use model ovarian carcinoma cell lines that exhibit varied ER function in growth and in transcriptional regulation and in tumor tissue where progesterone receptor (PR) expression appears to be uncoupled from ER expression. The specific aims are: (1) Use the model cell lines to determine the effects of E and antiestrogens on invasiveness by using a Matrigel invasion assay and on secretion of the protease, Cathepsin D and the 120kDa marker by Northern blotting, immunoprecipitations and Western blotting. (2) Identify ER variants and mutations in ovarian carcinoma cells and tumor tissue that exhibit altered ER function. We will use polymerase chain reaction, (PCR) and oligonucleotide primers to amplify sequences that encode known functional domains of ER. Direct sequencing, chemical mismatch cleavage and single stranded conformational polymorphism analysis of PCR products will be used to detect ER variants and mutations. (3) Determine whether ER phosphorylation patterns are altered in ovarian carcinoma cells that differ in their response to estrogen by immunoprecipitations and Western blotting 32P-labelled ER.